Method of extracting grease from grease-bearing materials.



C. R. MAYO. .METHOD OF EXTRAGTING GREASE FROM GREASE BEARING MATERIALS.

APPLICATION FILED NOV. 26. 1910.

Patented July 22, 1913.

6 SHEETS-SHEET 1.

C. R. MAYO.

METHOD OF EXTRACTING GREASE FROM GREASE BEARING MATERIALS.

APPLICATION FILED NOV.26,1910.

1,068,354. Patented July 22, 1913.

5 SHEETS-SHEET 2.

i/W W G. R. MAYO. METHOD OF EXTRACTING GREASE FROM GREASE BEARINGMATERIALS. APPLICATION FILED NOV.26, 1910.

1,068,354, Patented July 22, 1913.

5 SHEETS-SHEBT 3.

G. R. MAYO.

METHOD OF EXTRAGTING GREASE FROM GREASE BEARING MATERIALS. APPLICATIONFILED NOV. 26, 1910.

1,068,354. Patented July 22, 1913.

5 SHBBTSSHEET 4.

Jz X 7 2 C. R. MAYO.

METHOD OF EXTRACTING GREASE FROM GREASE BEARING MATERIALS.

APPLICATION FILED NOV. 26, 1910.

Patented July 22, 1913.

5 SHEETS-SHEET 5.

w ll ll /||||l||| lllllll fl l l lHN l lH H Hl lfl lHqHHHHHHHHUHHIHHHHHHHHHUHHHHHU l l HHH HJHHU HhHU CHARLES manna MAYO, orLONDON, ENGLANIVIV METHOD OF EXTRACT ING GREASE FROM GREASE-BEARINGMATERIALS.

Specification of Letters Patent.

Patented July 22, 1 913.

.Original application filed April 8, 1910, Serial No. 554,176. Dividedand this application filed November 26, 1910. Serial No. 594,314.

[0 all whom it may concern:

Be it known that I, CHARLES Ronnn'r MA-Yo, a subject of the King ofGreat Britain, residing at Aldermans House, Bishopsgate, in the, city ofLondon, England, have inventeda new and useful Method of ExtractingGrease from-Grease-Bearing Materials; and the application is a divisionof my application filed April 8, 1910, Serial No. 554,176, of which thefollowing is a specification.

The present invention relates to a method of, extracting grease andsimilar matter from and for treating .wool, skins, vtextiles and othermaterials.

The art'of extraction of grease, commonly known as degreasing, has beenpracticed for a number of years, and it has long been recognized thatsystems working under rcuced pressureoficr advantages in the way ofdistilling at low temperatures, and so on, and such systems havecomprised extractors, stills and condensers interconnected in variouswaysand adapted to be placed under reduced pressure or vacuum; also ithas been recognized that it is advantageous ..to

displace the solvent which is heavily laden" with grease, and cause itto overflow from the extractor into a still or vessel in which thesolvent is to be distilled oil from the grease. 7

Now, according to this invention, the vacuum principle is applied to aplant comprising an extractor or degreasing vessel, arranged so as toallow the contents to decant or overflow into the upper end of a stillor grease collector, which latter is connected' to a condenser, and forthis purpose a suction or vacuum pump is connected to the condenser, anddraws off from the extractor still and condenser any air which ispresent at the commencement of operations, or which may accumulate inthe plant, or be admitted thereto, from time to time, so that a partialor complete vacuum is constantly maintained by the pump. Of course, ifthere be'onee or more series of extractors the last member of a serieswould-overflow into the still.

A further feature of the present invention, which may be regarded assubsidiary to the foregoing principal improvement, consists in passingthe condensed solvent down through or into a column of liquid, .thesuction of the pump being applied to the space above the column, Thepump may deliver into a scrubber, either directly, in the known manner,or indirectly, as, for instance, by interposing between the pump and thescrubbera compression or air vessel in which the increased pressure towhich the small traces of solvent vapors are subjected, overcomes thevapor tension, and causes the vapors tocondense in the form of dew,thereby facilitating ,the action of the scrubber.

These features, and thecomplete method embodying such features, will behereinafter particularly described with reference to the accompanyingdrawings in whichz- .Figures 1 .and '1 represent a side elevation,partly in vertical section of a plant for performing .the methodembodying all of the features above referred to. Figs. 2 and 2 representa plan of Figs. 1 and 1; and Fig. ,3 is an end elevation of the pump,air vessel andscrubber seen to the left-hand Side of 1.

The description will be directed first of all more particularly to theconstruction and arrangement of the pieces of apparatus, afterward theirconnections will be describechand lastly :the carrying out of adegreasing operation with the apparatus according to the improvedmethod.

There may be any convenient number of extractors or degreasing vessels,but three are shown in .the drawings, and these are indicatedrespectively by the reference letters a, b, c. The vessel (1 is shown invertical section in Fig. l, and as all of the vessels (1,1), and o arealike, a description of the vessel a equally applies to the vessels 1)and c. The vessel-a is conveniently cylindrical, and stands upon a base(Z, being shown fitted around a central thickened portion of the base11. A second cylinder-c is fitted around the periphery of the base (I,and is shown as being'about two-thirds of the height of the vessel a.The'annular space f, between the vessel aand cylinder e is filled withliquid,

so as to constitute a heating jacket for the vessel (1.. A cover 9,capable of being fitted I gas-tightly upon the vessel a, carries asuitable vacuum gage h, and may be secured in position by the clampingbolts j, seen only on the vessels Z) and c, the hooked ends of whichtake under, say, a ring 7., fixed around the upper'end or rim of thevessel a. The vessels a, b and 0 may stand upon a bench or :framing l.The liquid in the continuously driven and maintains a conjackets f maybe kept at an even temperature by admitting steam thereto by branchpipes at connected with the steam pipe n, the branches m being shownimmersed in the liquid, and reaching almost to the bottom of the jacketspace f.

The still or grease collector 0 is somewhat similar in construction tothe extractors, as it. comprises a base p, an outer cylinder 9 inclosinga jacket space 1* in the liquid, within which a steam emission pipe 8 isimmersed. The pipe 8 is connected with the steam pipe n aforesaidthrough a coil t, and branch pipe'u, the heat from the coil t serving todistil off the solvent as hereinafter explained. The still 0 is shownsupported,

upon an extension '1; of the bench or framing l, and is also providedwith-a cover w and gage w.

The condenser comprises a coil g which may be formed of corrugated metalor otherwise in order to give a large cooling surface, and there may bea spray pipe 2' designed to project numerous sprays upward onto theinterior of a roof-shaped'batlle 1, from which the liquid drips down onto the coil 3 and cools the latter in known .manner. A vacuum gage 2 maybe fitted to the uppermost pipe of the coil y as shown. The condenserfurther comprises a closed vessel 3, containing acolumn of liquid, suchas water, and a pipe 4;, passing downward through the liquid column andopening near the bottom of the latter, the pipe 4 being connected bymeans of the pipe 5 with the discharge ori-,

fice of the condenser coil 3 If desired the length of the pipe 4 whichis immersed in the column of liquid may be such that it will have a veryconsiderable condensing action and in fact it might be arranged for allof the condensing action to take place beneath the surface of the liquidcolumn. At the lower end the vessel 3 opens into a vessel 6, which maybe the reservoir for the carbon bisulfid or other solvent, and suchsolvent being heavier than Water remains beneath the water column, andis sealed by the-latter; It is to be noted that the pipe 4 does not passdown to the reservoir 6, but only to near the bottom of the vessel 3, sothat any air sucked from the condenser is not -delivered into solvent,but only into the water in the vessel 3.

The suction or vacuum pump 7 is connected by the pipe 8 with thecondenser vessel 3, above the column of liquid, andthe pump ispreferably of that kind which is stantly uniform degree of vacuum in theapparatus, so that the said pump only does actual work whenever therehas been an admission of air to theapparatus. The delivery pipe 9 of thepump is led into a closed chamber 10, and an inverted U-shaped pipe 11opens at one end into the chamber 10,

or valve 13 is fitted on the pipe 11, so that' by'adjusting this valveany desired degree of compression can be obtained in the'vessel 10. Alsothe pipe 8 may be fitted with'a valve 14 and the pipe 5 with a valve115. A back pressure valve 114 n1ay also be fitted on the pipe 5 abovethe valve 115. The extracting or degreasing vessel a is connected at itsupper end by an overflow pipe 15 with the lower end of the vessel 5, acock 16 being fitted on the pipe 15; the vessel 1) is similarlyconnected with the Vessel c by pipe 17 fitted with cock 18. The vessel 0is connected by an overflow pipe 19 to a point'near to the top of thestill or. grease collector o and the pipe 19 has a control cock 20. Allof the overflow pipes 15, 17, and 19, lead from a point a short distancefrom the tops of the respective vessels. At their lower ends theextractors a, b, c, are connected to a common pipe 21 through the cooks22, and by suitably manipulating the latter, any two, or allthreevessels. can be placed in communication with one another. TheTconnection 23 for the overflow valve 20 on the vessel 0 is connected bya pipe 24 with the vessel or. through a cock 240 attached to the rear ofthe connection 23. The

pipe 21 is connected by a p'pe (having a cock 250 therein) with thireservoir 6. A

pipe 26 is connected with the pipe 8 and ing vessels a, b, 0, eachbranch 27 having a I cock 28. There may .also be a cook 40 on the pipe26 near to the pump. An air or steam pipe 29 has branches 30 connectingwith the bottoms of the extractors a, b, 0, each branch being fittedwith a cock 31.

The spray pipe 2 has connected to it a water supply pipe 32. A pipe 33,leading from the condenser vessel 3, and having a branch connection 34to the scrubbing vessel 12, and a second connection 35 with the airvessel 10 enables a transference of liquid from one vessel to the otherunder control of the cooks 36 and 37 on the branches 34 and 35respectively. A pipe 38 is connected be tween the scrubber 12 and thesuction pipe 8, and communication through this pipe can be opened by thecock 39 thereon.

A gage glass 11, is fitted to, the vessel 3, to enable the height of theliquid column to be observed. Gage glasses 42 Fig. 1, may be fitted tothe lower ends of the air vessel 10 and scrubber 12, to enable theheight of any accumulation of solvent in these vessels to be observed.

Each of the vessels a, b and c, and also the vessel 0, has communicationthrough branch pipes 43 fitted with valves 44, with a pipe 45, leadingto the upper end of the condenser coil 3 At the commencement ofoperations the vessels a, b, c and 0 may all be empty, and if this isthe case the vessels (1, b and c are each charged with wool, or othermaterial from which grease is to be extracted, to about the height shownin the vessel 0 in Fig. 1. The covers 9 of the vessels a, b and c arenow clamped down, also the cover w of vessel 0, if the last-named coverhas been removed. All of the valves might be closed except the valves 28and 40, and these being opened, and the pump set to work the vessels (1,b and 0 would be exhausted, and if meanwhile steam be admitted to thejacket's f by the pipes m, the contents of the vessels a, b, and obecoming heated would 've up any moisture which they containecfi and thevapors would be drawn off by the pump. The cocks 28 and 40 may now beclosed, and the cocks 14, 115, 44, 20, 18 and 16 opened so that the pump7 will now exhaust the vessel 3, the pipes 4 and 5, the coil 3 the pipesand 43, and the vessels 0, c, b and a. When a suflicient degree ofvacuum has been obtained the cock 22 of the vessel (1, and the cock 250in the pipe 25 are opened and grease solvent from the reservoir 6 ispermitted to flow under gravity or due to the a head of water in thevessel 3, through the pipes 25 and 21, into the vessel at, until thecontents of the vessel are submerged by the solvent. When a fresh chargeof solvent is permitted to flow from the reservoir 6 into the vessel (1,and drives before it the charge already in a, this charge enters thevessel 6 by the pipe 15 and submerges the contents of b. When anotherfresh charge of solvent flows into a,'the charge in the vessel 1) willbe displaced, and will overflow by the pipe 17 into vessel 0, and this,being now a solvent heavily laden with grease, is allowed to overflowinto the vessel 0 by the pipe 19, when fyet another fresh charge ofsolvent flows rom the reservoir 6 into the vessel (1, driving before itthe charge already in a, which will enter b, as aforesaid. If preferred,however, instead of admitting a fourth charge. to vessel a, the cocks250 and 16 can be closed, and the cook 22 on the vessel I; opened. Onwarming the water jacket of the vessel a,,pressure will be generated,and the solvent forced over from a through the pipe 21 to the vessel b,displacing the charge in b to c, and that in c to 0, as.aforesaid. Ifthe coil t in the vessel 0 has live steam passing through it thegrease-laden solvent will be distilled, the solvent evaporated beingdrawn off into the condenser coil where it is condensed, and passing asa liquid from thence through pipe 5, down the pipe 4, in the vessel 3,to the reservoir 6, beneath the column of Water in the vessel 3. When athird charge of solvent is admitted to a the charge first admitted to awill be found in c, and as the third charge to a (or of course, it mightbe the fourth) will be very little contaminated with grease, it may bereturned to the reservoir 6'. To do this all of the cocks on the vessel(1 may be closed, except the cock 22.' Under these circumstances thevessel (1 being warmed by its jacket, quickly generates pressure, whichdrives the solvent from a back into the reservoir 6. The-cock 22 is thenclosed and the cock 44 opened, and the vapors from the solvent stillclinging to the now degreased matter in a Will be drawn off through thecondenser. After a time the cock 44 to a may be closed, and the air orsteam, or steam and air cock 31, and the suction cock 28, may be opened,and a deodorizing current of air, or steam, or steam and air be passedthrough the degreased matter, such current being drawn off by the pump7, and passed through the air vessel 10, and scrubber 12'as hereinafterexplained. After closing all of the cocks on the "essel a, the lattermay be opened and the degreased matter removed, and a fresh charge ofgreasy material may be introduced. The charge of solvent which was firstin a, and is now in 0, may, after the exhaustion of the vessel a,through its cock 28, as before, he re-admitted to a by closing the cooks20 and 44 on the vessel 0 and the cock 18 on the vessel 6, and openingthe cock 240 on the pipe 24, and the cocks 22 beneath b and c, for whenthis has been done .the pressure which will be generated in thevessel 1) through the warming of the water jacket will drive the solventfrom the vessel b through the pipe 21 into the vessel 0, and thecontents of the vessel c-Will then over flow through the pipe 24 intothe vessel 0. The cock 22 on the vessel 5 may now be closed, and thecontents in the vessel 6 may be freed from the remaining solvent anddeodorized in the manner just previously described with reference to thevessel a. After this, the degreased material is removed from the vessel1), and the latter receives a fresh charge of material, and afterclosing and exhausting the vessel b, the solvent from the vessel a maybe driven into the vessel 6, by opening the cock 16, and the cocks 22 beneath the vessels at and c, and closing all other cocks except cock 44on the vessel 6, so that the pressure which is then generated in 0drives the solvent into a and the contents of the vessel It overflowinto I). The vessel 0, after being freed from the remaining solvent, asabove described, may now be opened in order to remove its contents, andto give it a fresh charge, the same procedure" being observed asdescribed with reference to the vessels a and b. It will be understoodthat it is very easy, before transferring solvent from the vessel 0 tothe vessel a, or

from c to b, to cause to overflow into the vessel 0 the up er layers ofsolvent laden with grease, and to transfer only the lower layers ofcomparatively grease-free .solvent. It will also be observed that whenin regular work, one charge only is caused to overflow into the vessel 0in each cycle. As the grease-laden solvent flows into the still 0, it isevaporated and led ofi' to the condenser, the pressure in the latterbeing lower, due to the condensation constantly taking place. It will bereadily recognized that the pump has very little work to do owing tothis fact, and that the pump is only required to suck out air which hasleaked into the apparatus, or which has been admitted when opening oneof the extractors a, b, or 0. The pressure of the atmosphere beinggreater than.

the normal pressure within the apparatus, or, at any rate, within thatpart of the apparatus which represents the closed circuit of thesolvent, the tendency is for air to leak into the'apparatus, and thesolvent vapors cannot, therefore, leak out.

The grease which collects within the vessel 0 may be drawn oil from timeto time, or as desired through the draw-oil cock 46. If desired, thevessel 0 may be provided with battles for the grease-laden solvent oremulsion to flow over, or with other devices of known character designedto facilitate the liberation of the solvent vapors from the grease.

Any air passing into the condenser coil y will pass with the vapors andliquid-through the pipes 5 and 4, and whereas the solvent will remainbeneath the column of water in the vessel 3, the solvent being heavierthan water, the air will rise through the water, and will be sucked offthrough the pipe 8. It will be noticed that the column of water in thevessel 3 not only serves to seal ofl' the solvent contained in thereservoir 6, but also serves to provide a considerable head, which willforce the solvent as quickly as desired into the extractors when thecocks 250 and 22 are opened. If preferred. however, the reservoir 6might be detached from the vessel 3, and might have its own column ofwater for sealing and pressure purposes, and in that case the spaceabove the water could be in communication with the suction pipe 8, sothat the whole system would still retain its low pressurecharacteristic, and all solvent would be water sealed.

Referring now more particularly to Fig. 3, it may be explained thatshould the pump draw off any air from the apparatus, as aforesaid, suchair in most cases will bear slight traces of solvent vapors which arevery" diflicult to extract and remove from such air, the retention ofthese last traces being due to vapor tension. In order to effectuallyremove these last traces the delivery of, air from the ump 7, instead ofbeing taken to the scrub directly, is first with a solvent draw-off cockand a gage.

Pressure is set up in the chamber 10, due to entry of any air from thepump, and this pressure can be regulated asdesired by closing oradjusting the cock 13, so that the pressure varies in accordance withthe freedcm of escape from the chamber 10. The pressure thus set up inthe chamber 10 releases practically all of the last traces of solventwhich are deposited in the form of dew, and any traces not so depositedwill pass on to the scrubber through the pipe 11. If desired thepressure in the chamber may be increased by the assistance of othermeans, for instance, by the admission of Water under pressure to thechamber while the valve 13 is closed or partly closed.

The lower end of the pipe 11 in the scrubber may be fitted, if desired,with a perforated rose, or ring, or spray nozzle, and the scrubber maybe fitted with baflles in .Order to cause the ascending air-bubbles toperforma tortuous course. If the air, after being compressed in thevessel 10, be allowed to stand therein for a time so that itstemperaturebecomes reduced, owing, say, to radiation of heat from the walls of thechamber, then, upon opening the cock 13, the air will suddenly expandinto the scrubber, the temperature will be still further reduced, andthe condensation of solvent vapors will be expedited; also thetemperature of the scrubbing liquid will be kept low, and will not beraised, as it otherwise might be, due to the heat given out incompresslng the am .What I claim and desire to secure by Letters Patentof the'United States is 1. The method of degreasing grease ladenmaterials which consists in subjecting them to a reduced pressure,supplying a solvent to the material, displacing the solvent when greaseladen and discharging same into a still by further supply of solventtosaid material, separating the solvent from the grease by distillation,condensing the distilled vapors, delivering gases, uncondensed vaporsand products of condensation to a column of liquid sucking awayuncondensed vaporseand gases escaping from said column and treating suchvapors and gases for the recovery therefrom of the last traces ofsolvent vapor.

2. The method of degreasing grease laden 7 materials which consists in.subjecting them to a reduced pressure, supplying a solvent to thematerial, displacing the solvent when grease laden and discharging sameinto a still by further supply of solvent to said material, separatingthe solvent from the grease by distillation, condensing the distilledvapors, delivering'gases, uncondensed vapors and the products ofcondensation to a column of liquid maintained ona body of sol-,vent,ma1nta1n1ng reduced pressure above the material, displacing thesolvent when grease laden and discharging same into a still by furthersupply of solvent to said material, separating the solvent from thegrease by distillation, condensing the distilled vapors, drawing gases,uncondensed vapors and the products of condensation down through aportion of a column of liquid, admit-ting said gases, vapors andproducts to said column at a point above the base of the latter, suckingaway uncondensed vapors and gases rising through and escaping at the topof said column and treating such vapors and gases for the recoverytherefrom of the last traces of solvent vapor.

4. The method of degreasing grease laden materials which consists insubjecting them to a reduced pressure, supplying a solvent to thematerial, displacing the solvent when grease laden and discharging sameinto a still by further supply of solvent to said material, separatingthe solvent from the grease by distillation, condensing the distilledvapors, drawing gases, uncondensed vapors and the products ofdistillation down through a portion of a column of less specific gravitythan said solvent, admitting said gases, vapors and products to saidcolumn at a point above the base of the latter, sucking uncondensedgases and vapors through said column, treating such gases and vapors forthe recovery therefrom of the last traces of solvent vapors andmaintaining said column at such a height as to provide an adequate headfor effecting said displacement, substantially as set forth.

, 5. The method of degreasing grease laden materials, which consists insubjecting them to a reduced pressure, supplying a solvent to thematerial to extract the grease therefrom, drawing off the resultantemulsion, distilling the latter, condensing the distilled vapors,drawing off the uncondensed gases and volatile products duringextraction, distillation and condensation, and subjecting the drawn offproducts to compression.

6. The method of degreasin grease laden materials, which consists in sujecting them to a reduced pressure, supplying a solvent to the materialto extract the grease therefrom, drawing oil the resultant emulsion,distilling the latter, condensing" the distilled vapors, drawing off theuncondensed gases and volatile products during extraction, distillationand condensation, subjecting the drawn off -products to, compression,and passing the compressed products through a column of liquid.

7. The method of degreasing grease laden materials which consists inheating the material, drawing off the vapor therefrom, subjecting thematerial to a vacuum, passing a solvent through the material to extractthe grease therefrom, drawing off the resultant emulsion, distilling thelatter, condensing the distilled vapors, drawing the products ofcondensation through a liquid seal of less specific gravity than thesolvent, admitting said products to said seal below the top of thelatter, maintaining an adequate head above the solvent to drive thelatter onto the material, drawing off the uncondensed gases and volatileproducts duringextraction, distillation and condensation, compressingthe drawn off products, and passing the compressed products through acolumn of liquid.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES ROBERT MAYO. Witnesses:

W. MORBEY, H. D. JAMEsoN.

